Carburetor



Dec. 9, 1924. l 1,519,081

R. COZETTE CARBURETOR Filed April l2 1920 Patented ec. 9, 1924 UNITEDSTATES REN cozn'rrn, or COURBEVOIE, FRANCE.

CARBURETOR.

Application filed yApril 12, 1920.

T0 all whom t m04/ concern:

Be it known that l. REN Cozn'rrn. a citizen of the French Republic,residing at No. 43 Rue Louis Blanc, Courbevoiej Seine, France, haveinvented certain new and useful improvements in Carburetors, of whichthe following is a specification.

This invention has tor its object to provide an improved 4carburetordesigned tor use with internal combustion engines in order to prod ce anexplosive mixture in which the proportions ot fuel and air are correctlydetermined for all speeoa ot the engine.

The improved carburetor comprises two small carburetors of which one,hereinafter described as the low speed carburetor, acts continuously,whilst the other, hereinafter designated as the high-speed carburetor,acts to supply fuel to the engine when the speed ot the engineincreases.

The invention consists therefore in a peculiar construction of thehigh-speed carburetor and in the regulation ot its delivery by means ofa valve that is adapted to be operated by the depression occurring inthe mixing chamber ot the carburetor.

A constructional form of the improved apparatus is illustrated by way of'example in the accompanying drawing wherein is illustrated adiagrannnatic vertical section of a carburetor in accordance with theinventi on.

As shown. the improved carburetor is provided as usual with a pipe. oleading to the inlet valve of the engine and in which there is arrangeda regulating throttle o. An inlet chamber c formed as a prolongation ofthis pipe, is in constant communication with a low speed carburetor dprovided with a nozzle d1. This chamber is closed at its lower end by avalve c which on being opened establishes communication between the saidchamber and the high speed carburetor provided at the nozzle f1 and theVenturi tube g.

The seat oi this valve is constituted` by the upper partof the Venturitube. 7L which is open at its base to the atmosphere, and communicatesthrough orilices 71 with a chamber j for the iow of the mixturefurnished by the high speed carburetor whose nozzle f1 is arranged inthe air intake passage f. rlhe guide rod of the valve passes through thetop of the chamber c' and carries Serial No. 373,221,

a. piston Z Working in a cylinder m which latter communicates throughthe orifice n with the atmosphere, and through the orifice o with theinlet chamber. This guide rod 7:: extends also under the valve e and isprefer ably tube-form throughout its length and constitutes a duct Zalwhich establishes communication between the Venturi tube and the spacesituated above the upper space ot the piston Zin such a manner as tosubject the .latter under certain conditions to the ctt'ects of thedepression existing in the carburetor.

It is to be noted that the lower edge of the rod terminates in a planebeneath the most restricted portion of the throat of the Venturi tube.The object of the arrangement is to vary the action on the valve and tobrake the valve at low and medium speeds and to raise the valve when theengine is revolving at or about its normal speed.

The improved carburetor operates as tollows 1When the engine isope-rating at low speed, the valve c being on its seat.. only the lowspeed carburetor d will be in operation.

At medium speeds, since the depression increases in the chamber c, thevalve will be acted upon by two forces, namely an upward force which isa result ot the depression existing in the chamber c and ot the area oitthe valve, and a. downward torce which is a result ot the weight ot' thevalve and of the action oi the diiierential preesure upon the surface otthe piston Z.

The result that the resistance to the opening ot the valve is determinedby the choice of the diameter ot the piston and ot the weight of thevalve. lt is to be noted on this point that this resistance must begreater in engines running a high compression than in engines havingonly a low compression, but that the lifting vtorce ot the valve mustalways be greater than the braking torce, that is for instance it P bethe weight ot the valve; l) the depression existing in the chamber c; Sthe area of the valve; and S1 the area ot the piston, there must alwaysthe venturi to enter said chamber, said air serving to compensate forthe increase in the fuel supplied by the nozzle Z1 as a result of theincrease in the depression.

if this depressio-n still increases, the valve Will lift a correspondingadditional amount, and since the velocity of the air passing thro-ughthe venturi increases, the nozzle f1 will begin to deliver in such amanner as to compensate for the insufficient delivery of the nozzle all,Nevertheless'the lift ot the valve Will be slightly brahed by thedepression in the chamber c acting through the orifice 0, and when, thevalve having continued its movement, the piston Z Will have reached andclosed the orifice n, the depression existing in the Venturi tube vfillart through the duct icl upon the upper surface of the piston and thedifferential pressure Will assist the rise of the valve.

On a further increase in the speed, the orifice fn, Will be againuncovered, but this time it is uncovered by the under surface ot' thepiston, and the admitted air Will destroy the depression which underthis surit'ace is exerting a braking o'l the lift of the valve. Thedifferential pressure will then raise the valve quickly to the end ofits travel.

The reverse operation Will take place ot course when the engine dropsfrom its normal speed down to low speed.

It Will be understood that this valve does not require the use of anyreturning spring, and that it moves out of the Way automatically as soonas the engine reaches its normal speed, so that it does no-t create anyobstacle in the piping.

llVhat I claim is In a device of the character described, incombination, a throttle controlled inlet pipe forming a main chamber; amedium and high speed carburetor having a Venturi tube and communicatingWith said chamber; a lov,T speed carburetor communicating With the innerend ofthe chamber, a substantially closed cylinder having a smallopening for establishing communication with the top ot the chamber andalso provided with a small opening in its lateral Wall near its base forestablishing communication With the atmos phere, a piston head operatingin the cylinder and coacting With the openings therein, a hollow rodcarried by the piston head and depending therefrom and slidable throughthe casing and having its lower edge normally arranged in a planebeneath the most restricted portion of the throat of the venturi, and avalve carried by the rod controlling the communication between saidchamber and the high speed carburetor substantially as and for thepurposes set forth.

In testimony whereof I aiiix my signature.

REN COZETTE`

